Stand-up bag leak detector

Abstract

The present invention relates to the technical field of leak detectors, in particular to discharge leak detectors; the technical problem to be solved by the present invention is to provide a leak detector for stand-up bags with higher detection efficiency. The leak detector for stand-up bags includes an input device, an output device and a flipping device fixed on a frame, the flipping device is located between the input device and the output device, the input device, the flipping device and the output device are sequentially arranged in the conveying direction of the stand-up bag, and also includes a bottle head detection device arranged below the flipping device, the bottle head detection device includes a first discharge electrode and a first receiving electrode, the first bracket is fixedly connected to the second bracket, the first receiving electrode is fixed on the first bracket, the first discharge electrode is rotatably arranged on the second bracket, the first receiving electrode is located above the first discharge electrode, the first receiving electrode and the first discharge electrode are between the first receiving electrode and the first discharge electrode for the bottle head detection station, and the axis of the first receiving electrode is perpendicular to the rotation axis of the first discharge electrode.

Description

Technical Field

[0001] The invention relates to the technical field of leak detectors, in particular to a discharge leak detector. Background Art

[0002] The existing leak detector includes an input device for inputting the bottle body, a flipping device for flipping the bottle body, and an output device for outputting the bottle body. The discharge electrode and the receiving electrode are connected to discharge the bottle body for leak detection, and the effect of leak detection on the whole of the small bottle is better. However, for larger bottles such as stand-up bags, the existing leak detector cannot perform partition detection on the bottle body when leak detection is performed, and the detection area span is large, which is easy to cause missed detection. The existing leak detector cannot perform partition detection on the bottle head, bottle body, and bottle bottom of the stand-up bag separately, and the detection efficiency is low. Summary of the invention

[0003] The technical problem to be solved by the present invention is to provide a stand-up bag leak detector with higher detection efficiency.

[0004] The technical solution adopted by the present invention to solve its technical problems is: a stand-up bag leak detector, including an input device, an output device and a flipping device fixed on a frame, the flipping device is located between the input device and the output device, the input device, the flipping device and the output device are arranged in sequence in the conveying direction of the stand-up bag, and also includes a bottle head detection device arranged below the flipping device, the bottle head detection device includes a first discharge electrode and a first receiving electrode, the first bracket is fixedly connected to the second bracket, the first receiving electrode is fixed on the first bracket, the first discharge electrode is rotatably arranged on the second bracket, the first receiving electrode is located above the first discharge electrode, the first receiving electrode and the first discharge electrode are between the first receiving electrode and the first discharge electrode for the bottle head detection station, the axis of the first receiving electrode is perpendicular to the rotation axis of the first discharge electrode.

[0005] Furthermore, the first discharge electrode is driven to rotate by a servo motor via a belt.

[0006] Furthermore, it also includes a synchronous tracking device, and the first bracket is fixed on the synchronous tracking device; the synchronous tracking device includes a driving motor and a conveyor belt, the first bracket is fixedly connected to the conveyor belt, the conveyor belt is connected to the driving shaft of the driving motor, and the first bracket is slidably matched with the guide rail through a slider.

[0007] Furthermore, there are at least two first discharge electrodes, which are symmetrically arranged about the rotation axis of the first discharge electrodes; and the first receiving electrodes include three types: iron wire, iron sheet and copper wire.

[0008] Furthermore, it also includes a bottle body detection device arranged near the output device, the bottle body detection device includes a first column, a second column, a second discharge electrode and a second receiving electrode, and a bottle body detection station is between the first column and the second column;

[0009] The second discharge electrode is rotatably disposed on the first column and the second column respectively, and the second receiving electrode is rotatably disposed near the second discharge electrode. The rotation axis of the second receiving electrode is parallel or perpendicular to the rotation axis of the second discharge electrode.

[0010] Furthermore, the second receiving electrode is arranged on a base located between the first column and the second column, and the rotation axis of the second receiving electrode is perpendicular to the rotation axis of the second discharge electrode.

[0011] Furthermore, the second receiving electrode is arranged on the first column or the second column, and the rotation axis of the second receiving electrode is parallel to the rotation axis of the second discharge electrode.

[0012] Furthermore, the end of the second discharge electrode is provided with a round chamfer, the end of the second receiving electrode is provided with a round chamfer, and the second discharge electrode is symmetrically arranged on the first column and the second column.

[0013] Furthermore, the invention also includes a bottle bottom detection device arranged near the output device, the bottle bottom detection device includes a third discharge electrode and a third receiving electrode, and also includes a first bracket and a second bracket, the third discharge electrode is rotatably arranged on the first bracket, the third receiving electrode is rotatably arranged on the second bracket, and a bottle bottom detection station is provided between the third discharge electrode and the third receiving electrode, and the rotation axis of the third discharge electrode is perpendicular to the rotation axis of the third receiving electrode.

[0014] Furthermore, there are at least two third discharge electrodes; the end of the third discharge electrode is in an arc shape; the third discharge electrode and the third receiving electrode are reset by a tension spring.

[0015] Furthermore, the third receiving electrode comprises an electrode body, the discharge portion of the electrode body is provided with tentacles, the discharge portion of the third receiving electrode is forked; the tip of the tentacle is arc-shaped; arc chamfers are provided between the tentacles; and there are at least three tentacles.

[0016] Furthermore, the flipping device is provided with a flipping clamping device for clamping the medicine bottle of the stand-up bag, including a clamping claw and a pull rod, the clamping claw and the pull rod are hinged, and also includes a guide plate fixed near the pull rod, the guide plate is provided with a guide groove, and the pull rod is provided with a guide column, and the guide column and the guide groove only slide together along the axial direction of the pull rod.

[0017] Furthermore, a rubber layer is provided on the side wall of the guide groove; a bearing is provided on the guide column, and the bearing and the guide groove are in rolling cooperation.

[0018] Furthermore, the guide groove is a through groove, and a detachable baffle is provided on the top of the guide groove.

[0019] Furthermore, it also includes a linear bearing fixed near the pull rod, and the pull rod and the linear bearing are slidably matched.

[0020] The invention has the beneficial effects that: the stand-up bag leak detector comprises an input device, an output device and a flip device fixed on a frame, the flip device is located between the input device and the output device, the input device, the flip device and the output device are sequentially arranged in the conveying direction of the stand-up bag, and also comprises a bottle head detection device arranged below the flip device, the bottle head detection device comprises a first discharge electrode and a first receiving electrode, the first bracket is fixedly connected to the second bracket, the first receiving electrode is fixed on the first bracket, the first discharge electrode is rotatably arranged on the second bracket, the first receiving electrode is located above the first discharge electrode, the first receiving electrode and the first discharge electrode are between the first receiving electrode and the first discharge electrode for the bottle head detection station, and the axis of the first receiving electrode is perpendicular to the rotation axis of the first discharge electrode. When the stand-up bag is flipped upside down by the flip device, the bottle head detection device detects the head of the stand-up bag, the first discharge electrode on the bottle head detection device can rotate, when the bottle head reaches the detection station, the first discharge electrode can rotate around the bottle head, the contact time between the first discharge electrode and the bottle head becomes longer, the contact probability between the bottle head and the discharge electrode is increased, and the leakage detection efficiency of the bottle head is improved, and the detection efficiency of the stand-up bag leak detector is higher. BRIEF DESCRIPTION OF THE DRAWINGS

[0021] Figure 1 This is a top view of the structure of the stand-up bag leak detector;

[0022] Figure 2 This is the AA cross-sectional view of the structure of the stand-up bag leak detector;

[0023] Figure 3 It is a three-dimensional schematic diagram of the structure of the flip clamping device;

[0024] Figure 4 It is a structural schematic diagram of the guide plate;

[0025] Figure 5 is a schematic diagram of the structure of the third receiving electrode;

[0026] Figure 6 It is a partial enlarged diagram of the structure of the third receiving electrode;

[0027] Figure 7 It is a three-dimensional schematic diagram of the structure of the bottle head detection device;

[0028] Figure 8 This is the structural front view of the bottle head detection device;

[0029] Fig. 9 It is a structural schematic diagram of a bottle bottom detection device;

[0030] Fig.10 It is a structural schematic diagram of a bottle bottom body detection device;

[0031] Fig.11 It is a structural schematic diagram of a bottle upper body detection device;

[0032] Components, parts and numbers in the figure: medicine bottle flipping and clamping device 1, clamping claw 101, guide plate 102, guide groove 1021, pull rod 103, guide column 1031, linear bearing 104, bottle head detection device 3, first receiving electrode 301, first discharge electrode 302, conveyor belt 303, drive motor 304, belt 305, second bracket 306, first bracket 307, bottle bottom detection device 4, fourth bracket 401, third receiving electrode 402, electrode body 4021, discharge part 40211, third discharge electrode 403, third bracket 404, tension spring 405, bottle body detection device 5, first column 501, second column 502, base 503, stand-up bag 504, second discharge electrode 505, second receiving electrode 506, input device 6, output device 7. DETAILED DESCRIPTION

[0033] The present invention will be further described below in conjunction with the accompanying drawings.

[0034] by Figure 2 The up, down, left, and right orientations shown are those of the corresponding parts.

[0035] like Figures 1 to 11 As shown, the stand-up bag leak detector includes an input device 6, an output device 7 and a flipping device fixed on a frame, the flipping device is located between the input device 6 and the output device, the input device 6, the flipping device and the output device 7 are sequentially arranged in the conveying direction of the stand-up bag, and also includes a bottle head detection device 3 arranged below the flipping device, the bottle head detection device 3 includes a first discharge electrode 302 and a first receiving electrode 301, a first bracket 307 is fixedly connected to a second bracket 306, the first receiving electrode 301 is fixed on the first bracket 307, the first discharge electrode 302 is rotatably arranged on the second bracket 306, the first receiving electrode 301 is located above the first discharge electrode 302, the first receiving electrode 301 and the first discharge electrode 302 are between the bottle head detection station, and the axis of the first receiving electrode 301 is perpendicular to the rotation axis of the first discharge electrode 302.

[0036] The input device 6 inputs the stand-up bag or other medicine bottles from the outside into the machine, and then transfers the medicine bottles to the flipping device for flipping, so that the stand-up bag presents upright, inverted or tilted postures in the machine. When the medicine bottle is in an inverted state, the bottle head of the medicine bottle is detected by the bottle head detection device. When the bottle head reaches the detection station of the bottle head detection device, the discharge electrode rotates around the bottle head and discharges to detect the head of the medicine bottle. After the detection, the medicine bottle continues to move with the flipping device, so that the medicine bottle gradually rises, returns to the right position and is transferred to the output device 7. The output device 7 is responsible for transmitting the stand-up bag or medicine bottle out of the machine or the next process.

[0037] In order to make the discharge electrode rotate accurately, the first discharge electrode 302 is driven to rotate by a servo motor through a belt 305 . The first discharge electrode 302 is driven to rotate by a servo motor through a belt 305 .

[0038] In order to shorten the detection time, the present invention further includes a synchronous tracking device, and the first bracket 307 is fixed on the synchronous tracking device. When the bottle head passes through the detection station upside down, the first discharge electrode 302 and the first receiving electrode 301 can move linearly with the bottle head, and the bottle head can be inspected while being transported by the flipping device. The synchronous tracking device includes a driving motor 304 and a conveyor belt 303, the first bracket 307 is fixedly connected to the conveyor belt 303, the conveyor belt 303 is connected to the driving shaft of the driving motor 304, and the first bracket 307 is slidably matched with the guide rail through a slider.

[0039] In order to improve the detection efficiency and make the detection sensitivity higher, there are at least two first discharge electrodes 302, and the first discharge electrodes 302 are symmetrically arranged about the rotation axis of the first discharge electrode 302; the first receiving electrode 301 has three types: iron wire, iron sheet and copper wire. The more first discharge electrodes 302 there are, the smaller the rotation angle of the first discharge electrode 302. The first receiving electrodes 301 of different shapes and materials have different resistances, which increases the diversity of detection and improves the sensitivity of detection.

[0040] In order to further improve the detection efficiency of the present invention, the present invention further includes a bottle body detection device 5 arranged near the output device 7, the bottle body detection device 5 includes a first column 501, a second column 502, a second discharge electrode 505 and a second receiving electrode 506, and a bottle body detection station is located between the first column 501 and the second column 502;

[0041] The second discharge electrode 505 is rotatably disposed on the first column 501 and the second column 502 , respectively. The second receiving electrode 506 is rotatably disposed near the second discharge electrode 505 . The rotation axis of the second receiving electrode 506 is parallel or perpendicular to the rotation axis of the second discharge electrode 505 .

[0042] The second receiving electrode 506 of the bottle body detection device 5 is located below the second discharge electrode 505. When the rotation axis of the second receiving electrode 506 is parallel to the rotation axis of the second discharge electrode 505, the bottle body is inverted with the mouth facing downward and passes through the detection station. The bottle body pushes the second discharge electrode 505 and the second receiving electrode 506 to rotate. At this time, the second discharge electrode 505 contacts the middle of the bottle body, and the second receiving electrode 506 contacts the bottle body near the mouth of the bottle, and the upper half of the bottle body is discharged and detected; when the rotation axis of the second receiving electrode 506 is perpendicular to the rotation axis of the second discharge electrode 505, the bottle body is upright with the mouth facing upward and passes through the detection station. The bottle body pushes the second discharge electrode 505 and the second receiving electrode 506 to rotate. At this time, the second discharge electrode 505 contacts the middle of the bottle body, and the second receiving electrode 506 contacts the bottom of the bottle, and the lower half of the bottle body is discharged and detected. The present invention can perform discharge detection on the upper and lower halves of the bottle body respectively, making the leak detection area more refined, avoiding the possibility of missed detection, and improving the efficiency of missed detection.

[0043] The bottle body detection device 5 can be divided into a bottle lower body detection device and a bottle upper body detection device. When the rotation axis of the second receiving electrode 506 is parallel to the rotation axis of the second discharge electrode 505, it is used as a bottle upper body detection device, and the second receiving electrode 506 can be set on the first column 501 or the second column 502, or on other structures on the leak detector; when the rotation axis of the second receiving electrode 506 is perpendicular to the rotation axis of the second discharge electrode 505, it is used as a bottle lower body detection device, and the second receiving electrode 506 can be set on the first column 501 or the second column 502, or on other structures on the leak detector.

[0044] An implementation of a bottle bottom body detection device is provided: the second receiving electrode 506 is disposed on a base 503 between the first column 501 and the second column 502 , and the rotation axis of the second receiving electrode 506 is perpendicular to the rotation axis of the second discharge electrode 505 .

[0045] An implementation of a bottle upper body detection device is provided: the second receiving electrode 506 is arranged on the first column 501 or the second column 502 , and the rotation axis of the second receiving electrode 506 is parallel to the rotation axis of the second discharge electrode 505 .

[0046] In order to prevent the second discharge electrode 505 and the second receiving electrode 506 from scratching the stand-up bag when they come into contact with the stand-up bag, the end of the second discharge electrode 505 is provided with a round chamfer, and the end of the second receiving electrode 506 is provided with a round chamfer;

[0047] In order to ensure good contact between the second discharge electrode 505 and the bottle body 504, and thus achieve good detection effect, the second discharge electrode 505 is symmetrically arranged on the first column 501 and the second column 502. The more second discharge electrodes 505 there are, the more contact points there are between the second discharge electrode 505 and the bottle body 504, and the lower the probability of poor contact between the second discharge electrode 505 and the bottle body 504.

[0048] In order to further improve the detection efficiency of the present invention, the present invention also includes a bottle bottom detection device 4 arranged near the output device, the bottle bottom detection device 4 includes a third discharge electrode 403 and a third receiving electrode 402, and also includes a third bracket 404 and a fourth bracket 401. The third discharge electrode 403 is rotatably arranged on the third bracket 404, and the third receiving electrode 402 is rotatably arranged on the fourth bracket 401. The bottle bottom detection station is between the third discharge electrode 403 and the third receiving electrode 402, and the rotation axis of the third discharge electrode 403 is perpendicular to the rotation axis of the third receiving electrode 402.

[0049] After the stand-up bag is transferred to the output device by the flipping device, the stand-up bag is in an upright state, and the stand-up bag is transported to the top of the third bracket 404, so that the stand-up bag contacts the third discharge electrode 403 and the third receiving electrode 402. The stand-up bag pushes the third discharge electrode 403 and the third receiving electrode 402 to rotate, so that the bottle bottom contacts the end of the third discharge electrode 403, and the third receiving electrode 402 contacts the lower part of the bottle body, and then the discharge leakage detection of the bottle bottom is performed. After the stand-up bag detection is completed, the stand-up bag continues to move, and the third discharge electrode 403 and the third receiving electrode 402 will return to their original positions under the action of external force. The bottle bottom detection device 4 can specifically detect leaks on the bottle bottom of the stand-up bag, so that the detection area of ​​the present invention is further refined and the detection efficiency is higher.

[0050] In order to avoid poor contact between the third discharge electrode 403 and the bottom of the bottle, there are at least two third discharge electrodes 403. The more third discharge electrodes 403 there are, the smaller the probability of poor contact between the third discharge electrode 403 and the bottom of the bottle, and the higher the detection efficiency.

[0051] In order to prevent the third discharge electrode 403 from scratching the bottom of the stand-up bag, the end of the third discharge electrode 403 is arc-shaped; the third discharge electrode 403 and the third receiving electrode 402 can be reset by a tension spring 405, or by other external forces, such as a motor, a rubber band or a spring.

[0052] The third receiving electrode 402 includes an electrode body 4021, and a discharge portion 40211 of the electrode body 4021 is provided with a tentacle, and the discharge portion 40211 of the third receiving electrode 402 is forked; the tip of the tentacle is arc-shaped; arc chamfers are provided between the tentacles; and there are at least three tentacles;

[0053] The forked discharge portion 40211 has at least two tentacles. When the bottle body passes through the detection position and pushes the third receiving electrode 402 to rotate, the bottle body contacts the tentacles on the third receiving electrode 402 in sequence, which increases the number of contacts between the bottle body and the third receiving electrode 402, that is, increases the contact time between the third receiving electrode 402 and the bottle body, so that the contact failure rate between the bottle body and the third receiving electrode 402 is reduced, thereby improving the detection efficiency.

[0054] In order to prevent the tentacles and the parts between the tentacles from scratching the stand-up bag 504, the tips of the tentacles are arc-shaped, and arc chamfers are provided between the tentacles; in order to achieve a good detection effect, there are at least three tentacles.

[0055] In order to make the flipping device more stable when flipping the stand-up bag 504, and thus improve the working reliability of the present invention, the flipping device is provided with a medicine bottle flipping clamping device 1 for clamping the stand-up bag, including a clamping claw 101 and a pull rod 103, the clamping claw 101 and the pull rod 103 are hinged, and also includes a guide plate 102 fixed near the pull rod 103, the guide plate 102 is provided with a guide groove 1021, the pull rod 103 is provided with a guide column 1031, and the guide column 1031 and the guide groove 1021 are only slidably matched along the axial direction of the pull rod 103.

[0056] The guide groove 1021 on the guide plate 102 slides with the guide column 1031 on the pull rod 103 to limit the radial movement of the pull rod 103, so that when the pull rod 103 is pushed and pulled quickly, it will not shake in the radial direction of the pull rod, avoiding the shaking of the clamping jaws 101, making the clamping jaws 101 clamp the stand-up bag 504 more stable.

[0057] In order to further avoid vibration caused by collision between the guide column 1031 and the guide groove 1021, a rubber layer is provided on the side wall of the guide groove 1021, which can absorb vibration and reduce the wear of the guide column 1031; in order to reduce the friction between the guide column 1031 and the guide groove 1021, a bearing 1032 is provided on the guide column 1031, and the bearing 1032 and the guide groove 1021 are in rolling fit.

[0058] In order to facilitate the disassembly and assembly of the bearing 1032, the guide groove 1021 is a through groove, and a detachable baffle is provided on the top of the guide groove 1021. The baffle is used to prevent the bearing from falling off and to block the oil.

[0059] In order to keep the motion trajectory of the pull rod 103 stable when the pull rod 103 is long, a linear bearing 104 is also included which is fixed near the pull rod 103 , and the pull rod 103 and the linear bearing 104 are in sliding cooperation.

Claims

1. A stand-up bag leak detector, comprising an input device (6), an output device (7) and a flipping device fixed on a frame, wherein the flipping device is located between the input device (6) and the output device, and the input device (6), the flipping device and the output device (7) are sequentially arranged in the conveying direction of the stand-up bag, characterized in that: It also includes a bottle head detection device (3) arranged below the flipping device, the bottle head detection device (3) including a first discharge electrode (302) and a first receiving electrode (301), the first bracket (307) is fixedly connected to the second bracket (306), the first receiving electrode (301) is fixed on the first bracket (307), the first discharge electrode (302) is rotatably arranged on the second bracket (306), the first receiving electrode (301) is located above the first discharge electrode (302), the first receiving electrode (301) and the first discharge electrode (302) are between the bottle head detection station, and the axis of the first receiving electrode (301) is perpendicular to the rotation axis of the first discharge electrode (302); It also includes a synchronous tracking device, the first bracket (307) is fixed on the synchronous tracking device; the synchronous tracking device includes a driving motor (304) and a conveyor belt (303), the first bracket (307) is fixedly connected to the conveyor belt (303), the conveyor belt (303) is connected to the driving shaft of the driving motor (304), and the first bracket (307) is slidably matched with the guide rail through a slider; there are at least two first discharge electrodes (302), and the first discharge electrodes (302) are symmetrically arranged about the rotation axis of the first discharge electrodes (302); the first receiving electrode (301) has three types of iron wire, iron sheet and copper wire; It also includes a bottle body detection device (5) arranged near the output device (7), the bottle body detection device (5) including a first column (501), a second column (502), a second discharge electrode (505) and a second receiving electrode (506), the first column (501) and the second column (502) being a bottle body detection station; the second discharge electrode (505) is rotatably arranged on the first column (501) and the second column (502), respectively, the second receiving electrode (506) is rotatably arranged near the second discharge electrode (505), and the rotation axis of the second receiving electrode (506) is parallel or perpendicular to the rotation axis of the second discharge electrode (505); It also includes a bottle bottom detection device (4) arranged near the output device, the bottle bottom detection device (4) includes at least two third discharge electrodes (403) and a third receiving electrode (402), and also includes a third bracket (404) and a fourth bracket (401), the third discharge electrode (403) is rotatably arranged on the third bracket (404), the third receiving electrode (402) is rotatably arranged on the fourth bracket (401), a bottle bottom detection station is located between the third discharge electrode (403) and the third receiving electrode (402), the rotation axis of the third discharge electrode (403) is perpendicular to the rotation axis of the third receiving electrode (402); the end of the third discharge electrode (403) is in an arc shape; the third discharge electrode (403) and the third receiving electrode (402) are reset by a tension spring (405); The third receiving electrode (402) comprises an electrode body (4021); a discharge portion (40211) of the electrode body (4021) is provided with a tentacle; the discharge portion (40211) of the third receiving electrode (402) is forked; the tip of the tentacle is arc-shaped; arc chamfers are provided between the tentacles; and there are at least three tentacles.

2. The stand-up bag leak detector according to claim 1, characterized in that: The first discharge electrode (302) is driven to rotate by a servo motor via a belt (305).

3. The stand-up bag leak detector according to claim 1, characterized in that: The second receiving electrode (506) is arranged on a base (503) located between the first column (501) and the second column (502), and the rotation axis of the second receiving electrode (506) is perpendicular to the rotation axis of the second discharge electrode (505).

4. The stand-up bag leak detector according to claim 1, characterized in that: The second receiving electrode (506) is arranged on the first column (501) or the second column (502), and the rotation axis of the second receiving electrode (506) is parallel to the rotation axis of the second discharge electrode (505).

5. The stand-up bag leak detector according to claim 1, characterized in that: The end of the second discharge electrode (505) is provided with a round chamfer, the end of the second receiving electrode (506) is provided with a round chamfer, and the second discharge electrode (505) is symmetrically arranged on the first column (501) and the second column (502).

6. The stand-up bag leak detector according to claim 1, characterized in that: The flipping device is provided with a medicine bottle flipping clamping device (1) for clamping a stand-up bag, comprising a clamping claw (101) and a pull rod (103), wherein the clamping claw (101) and the pull rod (103) are hinged, and further comprising a guide plate (102) fixed near the pull rod (103), wherein the guide plate (102) is provided with a guide groove (1021), and the pull rod (103) is provided with a guide column (1031), wherein the guide column (1031) and the guide groove (1021) are only connected along the pull rod (103). Axial sliding fit; a rubber layer is provided on the side wall of the guide groove (1021); a bearing (1032) is provided on the guide column (1031), and the bearing (1032) and the guide groove (1021) are rolling fit; the guide groove (1021) is a through groove, and a detachable baffle is provided on the top of the guide groove (1021); and also includes a linear bearing (104) fixed near the pull rod (103), and the pull rod (103) and the linear bearing (104) are sliding fit.

Images